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author | Gang He <GHe@suse.com> | 2020-02-03 17:33:45 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-02-04 03:05:23 +0000 |
commit | 2d797e9ff95ecbcf0a83d657928ed20579444857 (patch) | |
tree | 717497eb6ccc1c6915c08c99448b00d945909022 /fs/ocfs2/file.c | |
parent | d4e9056daedca3891414fe3c91de3449a5dad0f2 (diff) | |
download | linux-stable-2d797e9ff95ecbcf0a83d657928ed20579444857.tar.gz linux-stable-2d797e9ff95ecbcf0a83d657928ed20579444857.tar.bz2 linux-stable-2d797e9ff95ecbcf0a83d657928ed20579444857.zip |
ocfs2: fix oops when writing cloned file
Writing a cloned file triggers a kernel oops and the user-space command
process is also killed by the system. The bug can be reproduced stably
via:
1) create a file under ocfs2 file system directory.
journalctl -b > aa.txt
2) create a cloned file for this file.
reflink aa.txt bb.txt
3) write the cloned file with dd command.
dd if=/dev/zero of=bb.txt bs=512 count=1 conv=notrunc
The dd command is killed by the kernel, then you can see the oops message
via dmesg command.
[ 463.875404] BUG: kernel NULL pointer dereference, address: 0000000000000028
[ 463.875413] #PF: supervisor read access in kernel mode
[ 463.875416] #PF: error_code(0x0000) - not-present page
[ 463.875418] PGD 0 P4D 0
[ 463.875425] Oops: 0000 [#1] SMP PTI
[ 463.875431] CPU: 1 PID: 2291 Comm: dd Tainted: G OE 5.3.16-2-default
[ 463.875433] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
[ 463.875500] RIP: 0010:ocfs2_refcount_cow+0xa4/0x5d0 [ocfs2]
[ 463.875505] Code: 06 89 6c 24 38 89 eb f6 44 24 3c 02 74 be 49 8b 47 28
[ 463.875508] RSP: 0018:ffffa2cb409dfce8 EFLAGS: 00010202
[ 463.875512] RAX: ffff8b1ebdca8000 RBX: 0000000000000001 RCX: ffff8b1eb73a9df0
[ 463.875515] RDX: 0000000000056a01 RSI: 0000000000000000 RDI: 0000000000000000
[ 463.875517] RBP: 0000000000000001 R08: ffff8b1eb73a9de0 R09: 0000000000000000
[ 463.875520] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
[ 463.875522] R13: ffff8b1eb922f048 R14: 0000000000000000 R15: ffff8b1eb922f048
[ 463.875526] FS: 00007f8f44d15540(0000) GS:ffff8b1ebeb00000(0000) knlGS:0000000000000000
[ 463.875529] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 463.875532] CR2: 0000000000000028 CR3: 000000003c17a000 CR4: 00000000000006e0
[ 463.875546] Call Trace:
[ 463.875596] ? ocfs2_inode_lock_full_nested+0x18b/0x960 [ocfs2]
[ 463.875648] ocfs2_file_write_iter+0xaf8/0xc70 [ocfs2]
[ 463.875672] new_sync_write+0x12d/0x1d0
[ 463.875688] vfs_write+0xad/0x1a0
[ 463.875697] ksys_write+0xa1/0xe0
[ 463.875710] do_syscall_64+0x60/0x1f0
[ 463.875743] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 463.875758] RIP: 0033:0x7f8f4482ed44
[ 463.875762] Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 80 00 00 00
[ 463.875765] RSP: 002b:00007fff300a79d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[ 463.875769] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8f4482ed44
[ 463.875771] RDX: 0000000000000200 RSI: 000055f771b5c000 RDI: 0000000000000001
[ 463.875774] RBP: 0000000000000200 R08: 00007f8f44af9c78 R09: 0000000000000003
[ 463.875776] R10: 000000000000089f R11: 0000000000000246 R12: 000055f771b5c000
[ 463.875779] R13: 0000000000000200 R14: 0000000000000000 R15: 000055f771b5c000
This regression problem was introduced by commit e74540b28556 ("ocfs2:
protect extent tree in ocfs2_prepare_inode_for_write()").
Link: http://lkml.kernel.org/r/20200121050153.13290-1-ghe@suse.com
Fixes: e74540b28556 ("ocfs2: protect extent tree in ocfs2_prepare_inode_for_write()").
Signed-off-by: Gang He <ghe@suse.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/ocfs2/file.c')
-rw-r--r-- | fs/ocfs2/file.c | 14 |
1 files changed, 6 insertions, 8 deletions
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c index 9876db52913a..6cd5e4924e4d 100644 --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -2101,17 +2101,15 @@ static int ocfs2_is_io_unaligned(struct inode *inode, size_t count, loff_t pos) static int ocfs2_inode_lock_for_extent_tree(struct inode *inode, struct buffer_head **di_bh, int meta_level, - int overwrite_io, int write_sem, int wait) { int ret = 0; if (wait) - ret = ocfs2_inode_lock(inode, NULL, meta_level); + ret = ocfs2_inode_lock(inode, di_bh, meta_level); else - ret = ocfs2_try_inode_lock(inode, - overwrite_io ? NULL : di_bh, meta_level); + ret = ocfs2_try_inode_lock(inode, di_bh, meta_level); if (ret < 0) goto out; @@ -2136,6 +2134,7 @@ static int ocfs2_inode_lock_for_extent_tree(struct inode *inode, out_unlock: brelse(*di_bh); + *di_bh = NULL; ocfs2_inode_unlock(inode, meta_level); out: return ret; @@ -2177,7 +2176,6 @@ static int ocfs2_prepare_inode_for_write(struct file *file, ret = ocfs2_inode_lock_for_extent_tree(inode, &di_bh, meta_level, - overwrite_io, write_sem, wait); if (ret < 0) { @@ -2233,13 +2231,13 @@ static int ocfs2_prepare_inode_for_write(struct file *file, &di_bh, meta_level, write_sem); + meta_level = 1; + write_sem = 1; ret = ocfs2_inode_lock_for_extent_tree(inode, &di_bh, meta_level, - overwrite_io, - 1, + write_sem, wait); - write_sem = 1; if (ret < 0) { if (ret != -EAGAIN) mlog_errno(ret); |